From 4bd7a65f5fec2c2272b86ae72b839ba7ba357200 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Sat, 12 Mar 1994 03:26:12 +0000 Subject: * nlmconv.c (main): For PowerPC, call powerpc_build_stubs and powerpc_resolve_stubs. Use __GOT0, not __toc_start. Handle it if the start and end symbols are not in the text section. (struct powerpc_stub): New struct definition. (powerpc_stubs, powerpc_stub_insns): New static variables. (powerpc_initial_got_size): New static variable. (powerpc_build_stubs): New function. (powerpc_resolve_stubs): New function. (powerpc_mangle_relocs): Clear extraneous data in .got section. Rearrange reloc handling to handle ELF relocs that are not partial_inplace. Resolve PC relative relocs. --- binutils/ChangeLog | 16 ++ binutils/nlmconv.c | 509 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 504 insertions(+), 21 deletions(-) diff --git a/binutils/ChangeLog b/binutils/ChangeLog index f7e7e36..569583a 100644 --- a/binutils/ChangeLog +++ b/binutils/ChangeLog @@ -1,3 +1,19 @@ +start-sanitize-powerpc-netware +Fri Mar 11 22:20:48 1994 Ian Lance Taylor (ian@tweedledumb.cygnus.com) + + * nlmconv.c (main): For PowerPC, call powerpc_build_stubs and + powerpc_resolve_stubs. Use __GOT0, not __toc_start. Handle it if + the start and end symbols are not in the text section. + (struct powerpc_stub): New struct definition. + (powerpc_stubs, powerpc_stub_insns): New static variables. + (powerpc_initial_got_size): New static variable. + (powerpc_build_stubs): New function. + (powerpc_resolve_stubs): New function. + (powerpc_mangle_relocs): Clear extraneous data in .got section. + Rearrange reloc handling to handle ELF relocs that are not + partial_inplace. Resolve PC relative relocs. + +end-sanitize-powerpc-netware Wed Mar 9 13:48:11 1994 Steve Chamberlain (sac@jonny.cygnus.com) * ar.c (move_members): Fix it so that the abi positional modifiers diff --git a/binutils/nlmconv.c b/binutils/nlmconv.c index 5293c08..3979d29 100644 --- a/binutils/nlmconv.c +++ b/binutils/nlmconv.c @@ -36,6 +36,7 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include +#include #include "sysdep.h" #include "bucomm.h" /* Internal BFD NLM header. */ @@ -123,6 +124,13 @@ static void i386_mangle_relocs PARAMS ((bfd *, asection *, arelent ***, static void alpha_mangle_relocs PARAMS ((bfd *, asection *, arelent ***, bfd_size_type *, char *, bfd_size_type)); +/* start-sanitize-powerpc-netware */ +static void powerpc_build_stubs PARAMS ((bfd *, asymbol ***, unsigned int *)); +static void powerpc_resolve_stubs PARAMS ((bfd *, bfd *)); +static void powerpc_mangle_relocs PARAMS ((bfd *, asection *, arelent ***, + bfd_size_type *, char *, + bfd_size_type)); +/* end-sanitize-powerpc-netware */ static void default_mangle_relocs PARAMS ((bfd *, asection *, arelent ***, bfd_size_type *, char *, bfd_size_type)); @@ -154,7 +162,7 @@ main (argc, argv) bfd *outbfd; asymbol **newsyms, **outsyms; unsigned int symcount, newsymalloc, newsymcount; - asection *bss_sec, *data_sec; + asection *text_sec, *bss_sec, *data_sec; bfd_vma vma; bfd_size_type align; asymbol *endsym; @@ -362,10 +370,21 @@ main (argc, argv) || ! bfd_set_section_alignment (outbfd, bss_sec, 1)) bfd_fatal ("make .bss section"); } +/* start-sanitize-powerpc-netware */ + + /* For PowerPC NetWare we need to build stubs for calls to undefined + symbols. Because each stub requires an entry in the TOC section + which must be at the same location as other entries in the TOC + section, we must do this before determining where the TOC section + goes in setup_sections. */ + powerpc_build_stubs (inbfd, &symbols, &symcount); +/* end-sanitize-powerpc-netware */ /* Set up the sections. */ bfd_map_over_sections (inbfd, setup_sections, (PTR) outbfd); + text_sec = bfd_get_section_by_name (outbfd, NLM_CODE_NAME); + /* The .bss section immediately follows the .data section. */ data_sec = bfd_get_section_by_name (outbfd, NLM_INITIALIZED_DATA_NAME); if (data_sec != NULL) @@ -462,7 +481,8 @@ main (argc, argv) /* Force _edata and _end to be defined. This would normally be done by the linker, but the manipulation of the common symbols will confuse it. */ - if (bfd_asymbol_name (sym)[0] == '_' + if ((sym->flags & BSF_DEBUGGING) == 0 + && bfd_asymbol_name (sym)[0] == '_' && bfd_get_section (sym) == &bfd_und_section) { if (strcmp (bfd_asymbol_name (sym), "_edata") == 0) @@ -475,7 +495,21 @@ main (argc, argv) sym->section = bss_sec; endsym = sym; } - } +/* start-sanitize-powerpc-netware */ + /* For PowerPC NetWare, we define __GOT0. This is the start + of the .got section. */ + if (bfd_get_arch (inbfd) == bfd_arch_powerpc + && strcmp (bfd_asymbol_name (sym), "__GOT0") == 0) + { + asection *got_sec; + + got_sec = bfd_get_section_by_name (inbfd, ".got"); + assert (got_sec != (asection *) NULL); + sym->value = got_sec->output_offset; + sym->section = got_sec->output_section; + } +/* end-sanitize-powerpc-netware */ + } /* If this is a global symbol, check the export list. */ if ((sym->flags & (BSF_EXPORT | BSF_GLOBAL)) != 0) @@ -554,29 +588,55 @@ main (argc, argv) } /* See if it's one of the special named symbols. */ - if (strcmp (bfd_asymbol_name (sym), start_procedure) == 0) - { - if (! bfd_set_start_address (outbfd, bfd_asymbol_value (sym))) - bfd_fatal ("set start address"); - gotstart = true; - } - if (strcmp (bfd_asymbol_name (sym), exit_procedure) == 0) - { - nlm_fixed_header (outbfd)->exitProcedureOffset = - bfd_asymbol_value (sym); - gotexit = true; - } - if (check_procedure != NULL - && strcmp (bfd_asymbol_name (sym), check_procedure) == 0) + if ((sym->flags & BSF_DEBUGGING) == 0) { - nlm_fixed_header (outbfd)->checkUnloadProcedureOffset = - bfd_asymbol_value (sym); - gotcheck = true; + bfd_vma val; + + /* FIXME: If these symbols are not in the .text section, we + add the .text section size to the value. This may not be + correct for all targets. I'm not sure how this should + really be handled. */ + if (strcmp (bfd_asymbol_name (sym), start_procedure) == 0) + { + val = bfd_asymbol_value (sym); + if (bfd_get_section (sym) == data_sec + && text_sec != (asection *) NULL) + val += bfd_section_size (outbfd, text_sec); + if (! bfd_set_start_address (outbfd, val)) + bfd_fatal ("set start address"); + gotstart = true; + } + if (strcmp (bfd_asymbol_name (sym), exit_procedure) == 0) + { + val = bfd_asymbol_value (sym); + if (bfd_get_section (sym) == data_sec + && text_sec != (asection *) NULL) + val += bfd_section_size (outbfd, text_sec); + nlm_fixed_header (outbfd)->exitProcedureOffset = val; + gotexit = true; + } + if (check_procedure != NULL + && strcmp (bfd_asymbol_name (sym), check_procedure) == 0) + { + val = bfd_asymbol_value (sym); + if (bfd_get_section (sym) == data_sec + && text_sec != (asection *) NULL) + val += bfd_section_size (outbfd, text_sec); + nlm_fixed_header (outbfd)->checkUnloadProcedureOffset = val; + gotcheck = true; + } } } if (endsym != NULL) - endsym->value = bfd_get_section_size_before_reloc (bss_sec); + { + endsym->value = bfd_get_section_size_before_reloc (bss_sec); + + /* FIXME: If any relocs referring to _end use inplace addends, + then I think they need to be updated. This is handled by + i386_mangle_relocs. Is it needed for any other object + formats? */ + } if (newsymcount == 0) outsyms = symbols; @@ -788,6 +848,11 @@ main (argc, argv) nlm_version_header (outbfd)->year = ptm->tm_year + 1900; strncpy (version_hdr->stamp, "VeRsIoN#", 8); } +/* start-sanitize-powerpc-netware */ + + /* Resolve the stubs we build for PowerPC NetWare. */ + powerpc_resolve_stubs (inbfd, outbfd); +/* end-sanitize-powerpc-netware */ /* Copy over the sections. */ bfd_map_over_sections (inbfd, copy_sections, (PTR) outbfd); @@ -1034,6 +1099,10 @@ select_output_format (arch, mach, bigendian) return "nlm32-sparc"; case bfd_arch_alpha: return "nlm32-alpha"; +/* start-sanitize-powerpc-netware */ + case bfd_arch_powerpc: + return "nlm32-powerpc"; +/* end-sanitize-powerpc-netware */ default: fprintf (stderr, "%s: no default NLM format for %s\n", program_name, bfd_printable_arch_mach (arch, mach)); @@ -1217,6 +1286,12 @@ mangle_relocs (outbfd, insec, relocs_ptr, reloc_count_ptr, contents, alpha_mangle_relocs (outbfd, insec, relocs_ptr, reloc_count_ptr, contents, contents_size); break; +/* start-sanitize-powerpc-netware */ + case bfd_arch_powerpc: + powerpc_mangle_relocs (outbfd, insec, relocs_ptr, reloc_count_ptr, + contents, contents_size); + break; +/* end-sanitize-powerpc-netware */ default: default_mangle_relocs (outbfd, insec, relocs_ptr, reloc_count_ptr, contents, contents_size); @@ -1514,6 +1589,398 @@ alpha_mangle_relocs (outbfd, insec, relocs_ptr, reloc_count_ptr, contents, (*relocs)->address += insec->output_offset; } } +/* start-sanitize-powerpc-netware */ + +/* We keep a linked list of stubs which we must build. Because BFD + requires us to know the sizes of all sections before we can set the + contents of any, we must figure out which stubs we want to build + before we can actually build any of them. */ + +struct powerpc_stub +{ + /* Next stub in linked list. */ + struct powerpc_stub *next; + + /* Symbol whose value is the start of the stub. This is a symbol + whose name begins with `.'. */ + asymbol *start; + + /* Symbol we are going to create a reloc against. This is a symbol + with the same name as START but without the leading `.'. */ + asymbol *reloc; + + /* The TOC index for this stub. This is the index into the TOC + section at which the reloc is created. */ + unsigned int toc_index; +}; + +/* The linked list of stubs. */ + +static struct powerpc_stub *powerpc_stubs; + +/* This is what a stub looks like. The first instruction will get + adjusted with the correct TOC index. */ + +static unsigned long powerpc_stub_insns[] = +{ + 0x81820000, /* lwz r12,0(r2) */ + 0x90410014, /* stw r2,20(r1) */ + 0x800c0000, /* lwz r0,0(r12) */ + 0x804c0004, /* lwz r2,r(r12) */ + 0x7c0903a6, /* mtctr r0 */ + 0x4e800420, /* bctr */ + 0, /* Traceback table. */ + 0xc8000, + 0 +}; + +#define POWERPC_STUB_INSN_COUNT \ + (sizeof powerpc_stub_insns / sizeof powerpc_stub_insns[0]) + +#define POWERPC_STUB_SIZE (4 * POWERPC_STUB_INSN_COUNT) + +/* Each stub uses a four byte TOC entry. */ +#define POWERPC_STUB_TOC_ENTRY_SIZE (4) + +/* The original size of the .got section. */ +static bfd_size_type powerpc_initial_got_size; + +/* Look for all undefined symbols beginning with `.', and prepare to + build a stub for each one. */ + +static void +powerpc_build_stubs (inbfd, symbols_ptr, symcount_ptr) + bfd *inbfd; + asymbol ***symbols_ptr; + unsigned int *symcount_ptr; +{ + asection *stub_sec; + asection *got_sec; + unsigned int got_base; + unsigned int i; + unsigned int symcount; + unsigned int stubcount; + + /* Make a section to hold stubs. We don't set SEC_HAS_CONTENTS for + the section to prevent copy_sections from reading from it. */ + stub_sec = bfd_make_section (inbfd, ".stubs"); + if (stub_sec == (asection *) NULL + || ! bfd_set_section_flags (inbfd, stub_sec, + (SEC_CODE + | SEC_RELOC + | SEC_ALLOC + | SEC_LOAD)) + || ! bfd_set_section_alignment (inbfd, stub_sec, 2)) + bfd_fatal (".stubs"); + + /* Get the TOC section, which is named .got. */ + got_sec = bfd_get_section_by_name (inbfd, ".got"); + if (got_sec == (asection *) NULL) + { + got_sec = bfd_make_section (inbfd, ".got"); + if (got_sec == (asection *) NULL + || ! bfd_set_section_flags (inbfd, got_sec, + (SEC_DATA + | SEC_RELOC + | SEC_ALLOC + | SEC_LOAD + | SEC_HAS_CONTENTS)) + || ! bfd_set_section_alignment (inbfd, got_sec, 2)) + bfd_fatal (".got"); + } + + powerpc_initial_got_size = bfd_section_size (inbfd, got_sec); + got_base = powerpc_initial_got_size; + got_base = (got_base + 3) &~ 3; + + stubcount = 0; + + symcount = *symcount_ptr; + for (i = 0; i < symcount; i++) + { + asymbol *sym; + asymbol *newsym; + char *newname; + struct powerpc_stub *item; + + sym = (*symbols_ptr)[i]; + + /* We must make a stub for every undefined symbol whose name + starts with '.'. */ + if (bfd_asymbol_name (sym)[0] != '.' + || bfd_get_section (sym) != &bfd_und_section) + continue; + + /* Make a new undefined symbol with the same name but without + the leading `.'. */ + newsym = (asymbol *) xmalloc (sizeof (asymbol)); + *newsym = *sym; + newname = (char *) xmalloc (strlen (bfd_asymbol_name (sym))); + strcpy (newname, bfd_asymbol_name (sym) + 1); + newsym->name = newname; + + /* Define the `.' symbol to be in the stub section. */ + sym->section = stub_sec; + sym->value = stubcount * POWERPC_STUB_SIZE; + sym->flags = BSF_LOCAL; + + /* Add this stub to the linked list. */ + item = (struct powerpc_stub *) xmalloc (sizeof (struct powerpc_stub)); + item->start = sym; + item->reloc = newsym; + item->toc_index = got_base + stubcount * POWERPC_STUB_TOC_ENTRY_SIZE; + + item->next = powerpc_stubs; + powerpc_stubs = item; + + ++stubcount; + } + + if (stubcount > 0) + { + asymbol **s; + struct powerpc_stub *l; + + /* Add the new symbols we just created to the symbol table. */ + *symbols_ptr = (asymbol **) xrealloc ((char *) *symbols_ptr, + ((symcount + stubcount) + * sizeof (asymbol))); + *symcount_ptr += stubcount; + s = &(*symbols_ptr)[symcount]; + for (l = powerpc_stubs; l != (struct powerpc_stub *) NULL; l = l->next) + *s++ = l->reloc; + + /* Set the size of the .stubs section and increase the size of + the .got section. */ + if (! bfd_set_section_size (inbfd, stub_sec, + stubcount * POWERPC_STUB_SIZE) + || ! bfd_set_section_size (inbfd, got_sec, + (got_base + + (stubcount + * POWERPC_STUB_TOC_ENTRY_SIZE)))) + bfd_fatal ("stub section sizes"); + } +} + +/* Resolve all the stubs for PowerPC NetWare. We fill in the contents + of the output section, and create new relocs in the TOC. */ + +static void +powerpc_resolve_stubs (inbfd, outbfd) + bfd *inbfd; + bfd *outbfd; +{ + bfd_byte buf[POWERPC_STUB_SIZE]; + unsigned int i; + unsigned int stubcount; + arelent **relocs; + asection *got_sec; + arelent **r; + struct powerpc_stub *l; + + if (powerpc_stubs == (struct powerpc_stub *) NULL) + return; + + for (i = 0; i < POWERPC_STUB_INSN_COUNT; i++) + bfd_put_32 (outbfd, (bfd_vma) powerpc_stub_insns[i], buf + i * 4); + + got_sec = bfd_get_section_by_name (inbfd, ".got"); + assert (got_sec != (asection *) NULL); + assert (got_sec->output_section->orelocation == (arelent **) NULL); + + stubcount = 0; + for (l = powerpc_stubs; l != (struct powerpc_stub *) NULL; l = l->next) + ++stubcount; + relocs = (arelent **) xmalloc (stubcount * sizeof (arelent *)); + + r = relocs; + for (l = powerpc_stubs; l != (struct powerpc_stub *) NULL; l = l->next) + { + arelent *reloc; + + /* Adjust the first instruction to use the right TOC index. */ + bfd_put_32 (outbfd, (bfd_vma) powerpc_stub_insns[0] + l->toc_index, buf); + + /* Write this stub out. */ + if (! bfd_set_section_contents (outbfd, + bfd_get_section (l->start), + buf, + l->start->value, + POWERPC_STUB_SIZE)) + bfd_fatal ("writing stub"); + + /* Create a new reloc for the TOC entry. */ + reloc = (arelent *) xmalloc (sizeof (arelent)); + reloc->sym_ptr_ptr = &l->reloc; + reloc->address = l->toc_index + got_sec->output_offset; + reloc->addend = 0; + reloc->howto = bfd_reloc_type_lookup (inbfd, BFD_RELOC_32); + + *r++ = reloc; + } + + bfd_set_reloc (outbfd, got_sec->output_section, relocs, stubcount); +} + +/* Adjust relocation entries for PowerPC NetWare. We do not output + TOC relocations. The object code already contains the offset from + the TOC pointer. When the function is called, the TOC register, + r2, will be set to the correct TOC value, so there is no need for + any further reloc. */ + +/*ARGSUSED*/ +static void +powerpc_mangle_relocs (outbfd, insec, relocs_ptr, reloc_count_ptr, contents, + contents_size) + bfd *outbfd; + asection *insec; + register arelent ***relocs_ptr; + bfd_size_type *reloc_count_ptr; + char *contents; + bfd_size_type contents_size; +{ + const reloc_howto_type *toc_howto; + bfd_size_type reloc_count; + register arelent **relocs; + register bfd_size_type i; + + toc_howto = bfd_reloc_type_lookup (insec->owner, BFD_RELOC_PPC_TOC16); + if (toc_howto == (reloc_howto_type *) NULL) + abort (); + + /* If this is the .got section, clear out all the contents beyond + the initial size. We must do this here because copy_sections is + going to write out whatever we return in the contents field. */ + if (strcmp (bfd_get_section_name (insec->owner, insec), ".got") == 0) + memset (contents + powerpc_initial_got_size, 0, + (bfd_get_section_size_after_reloc (insec) + - powerpc_initial_got_size)); + + reloc_count = *reloc_count_ptr; + relocs = *relocs_ptr; + for (i = 0; i < reloc_count; i++) + { + arelent *rel; + asymbol *sym; + bfd_vma symvalue; + + rel = *relocs++; + sym = *rel->sym_ptr_ptr; + + /* We must be able to resolve all PC relative relocs at this + point. If we get a branch to an undefined symbol we build a + stub, since NetWare will resolve undefined symbols into a + pointer to a function descriptor. */ + if (rel->howto->pc_relative) + { + /* This check for whether a symbol is in the same section as + the reloc will be wrong if there is a PC relative reloc + between two sections both of which were placed in the + same output section. This should not happen. */ + if (bfd_get_section (sym) != insec->output_section) + fprintf (stderr, "%s: unresolved PC relative reloc against %s\n", + program_name, bfd_asymbol_name (sym)); + else + { + bfd_vma val; + + assert (rel->howto->size == 2 && rel->howto->pcrel_offset); + val = bfd_get_32 (outbfd, (bfd_byte *) contents + rel->address); + val = ((val &~ rel->howto->dst_mask) + | (((val & rel->howto->src_mask) + + (sym->value - rel->address) + + rel->addend) + & rel->howto->dst_mask)); + bfd_put_32 (outbfd, val, (bfd_byte *) contents + rel->address); + + /* If this reloc is against a symbol whose name begins + with a `.', and the next instruction is + cror 31,31,31 + then we replace the next instruction with + lwz r2,20(r1) + This reloads the TOC pointer after a call. */ + if (bfd_asymbol_name (sym)[0] == '.' + && (bfd_get_32 (outbfd, + (bfd_byte *) contents + rel->address + 4) + == 0x4ffffb82)) /* cror 31,31,31 */ + bfd_put_32 (outbfd, (bfd_vma) 0x80410014, /* lwz r2,20(r1) */ + (bfd_byte *) contents + rel->address + 4); + + --*reloc_count_ptr; + --relocs; + memmove (relocs, relocs + 1, + (size_t) ((reloc_count - 1) * sizeof (arelent *))); + continue; + } + } + + /* When considering a TOC reloc, we do not want to include the + symbol value. The symbol will be start of the TOC section + (which is named .got). We do want to include the addend. */ + if (rel->howto == toc_howto) + symvalue = 0; + else + symvalue = sym->value; + + /* If this is a relocation against a symbol with a value, or + there is a reloc addend, we need to update the addend in the + object file. */ + if (symvalue + rel->addend != 0) + { + bfd_vma val; + + switch (rel->howto->size) + { + case 1: + val = bfd_get_16 (outbfd, + (bfd_byte *) contents + rel->address); + val = ((val &~ rel->howto->dst_mask) + | (((val & rel->howto->src_mask) + + symvalue + + rel->addend) + & rel->howto->dst_mask)); + if ((bfd_signed_vma) val < - 0x8000 + || (bfd_signed_vma) val >= 0x8000) + fprintf (stderr, + "%s: overflow when adjusting relocation against %s\n", + program_name, bfd_asymbol_name (sym)); + bfd_put_16 (outbfd, val, (bfd_byte *) contents + rel->address); + break; + + case 2: + val = bfd_get_32 (outbfd, + (bfd_byte *) contents + rel->address); + val = ((val &~ rel->howto->dst_mask) + | (((val & rel->howto->src_mask) + + symvalue + + rel->addend) + & rel->howto->dst_mask)); + bfd_put_32 (outbfd, val, (bfd_byte *) contents + rel->address); + break; + + default: + abort (); + } + + rel->sym_ptr_ptr = bfd_get_section (sym)->symbol_ptr_ptr; + rel->addend = 0; + } + + /* Now that we have incorporated the addend, remove any TOC + relocs. */ + if (rel->howto == toc_howto) + { + --*reloc_count_ptr; + --relocs; + memmove (relocs, relocs + 1, + (size_t) ((reloc_count - i) * sizeof (arelent *))); + continue; + } + + rel->address += insec->output_offset; + } +} +/* end-sanitize-powerpc-netware */ /* Name of linker. */ #ifndef LD_NAME -- cgit v1.1